• Archives of Pharmacal Research
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• v.12 no.1
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• pp.58-61
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• 1989

Studies of selectivity of hydrogen bond formation in chiral solute-solvent systems have been performed by $^1H\;and\;^{13}C$ nuclear magnetic resonance techniques. These data are correlated with the results of gas chromatographic investigations of the same systems. Interactions between the optically active solvent(N-(N-benzoyl-L-amino acid)-anilide) and optically active solute (N-trifluoroacetyl -L-alanyl isopropyl ester) were examined. NMR evidence indicated that hydrogen bonding interaction occurred between two N-H portion and on peptidyl carbonyl portion in stationary phase and solute molecule on three points. The association constants of solvent-solute interaction were calculated and the structure of the diastereomeric association complex between N-(N-benzoyl-L-valyl)-anilide and N-TFA-L-alanyl isopropyl ester was proposed.

• Archives of Pharmacal Research
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• v.26 no.12
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• pp.997-1001
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• 2003

This paper deals with chiral enzymatic resolution of 4-arylthio-2-butanols by lipase to prepare potential intermediates of $\beta$-lactam antibiotics. Among several lipases employed, lipase P type enzyme gave the highest ee value to prepare (R)-4-arylthio-2-butyl acetate. The enzymatic resolution of phenyl substituted alcohol (6a) using lipase P showed the highest ee value (99.7%) among those of 4-arylthio-2-butanol derivatives. Lipase P mediated hydrolysis of acylester 7a gave also (R)-alcohol 6a selectively. For determination of enantiomeric purity of these enzymatic resolved analytes, liquid chromatographic analysis was performed using two coupled Chiralcel OD and (R,R)-WhelkO chiral column.

• YAKHAK HOEJI
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• v.53 no.2
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• pp.60-68
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• 2009

In terms of chiral issue, two enantiomers of chiral drugs often differ significantly in their pharmacological, toxicological and pharmacokinetic profile. Chiral switches of racemic drugs have been redeveloped as single enantiomers. Several chiral resolution techniques in chirotechnology are introduced and the most used chiral HPLC chromatographic method among several chiral analysis techniques is described with its several advantages. Several types of chiral HPLC columns derived from their chiral selectors are discussed with their property and applications for enantiomer separation.

• YAKHAK HOEJI
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• v.29 no.6
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• pp.147-155
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• 1985

이글에서는 예를들어 immunoaffinity chromatography, HPLC및 고압에서 신속하게 분리될수 있게 해주는 새로운 chromatographic media (FPLC)등이 서둘러 개발되고 있는데 본문에섬는 최근에 개발되고 있는 새로운 high resolution 기술을 중심으로 하여 경제성있는 고순도의 rDNA 산물의 회수방법에 대하여 토론하고자 한다. 또한 이들의 정제 방법에 의한 rDNA 산물의 회수에 대한 한계성을 검토하고 최근에 활발히 개발되고 있는 rDNA 조작에 의해 발효산물의 추출및 정제를 용이하게 해줌으로 고수득률과 고순도의 회수를 가능하게 해주는 "upstream processing"기술과 정제 기술의 병용방법에 관하여 집중적으로 토론하고자 한다.

• Bulletin of the Korean Chemical Society
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• v.29 no.9
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• pp.1850-1852
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• 2008

• Bulletin of the Korean Chemical Society
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• v.12 no.3
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• pp.304-309
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• 1991

Target transformation factor analysis is applied to analyze the components of unresolved fraction in the elution curve of La, Pr and Gd which is obtained using the chelate agent- impregnated resin and 0.7 M hydrochloric acid as an eluent. We determined the number of components contributing to the unresolved fractions and verified the presence of suspected components.

• Proceedings of the PSK Conference
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• 2003.04a
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• pp.285.1-285.1
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• 2003

ChiroSil RCA(+) and SCA(-) HPLC chiral stationary phases (CSPs) developed by covalently bonding (+)- and (-)-(18-crown-6)-2,3,11,12-tetracarboxylic acid (18-C-6-T A) to silica gel were employed for enantioresolution of racemic amino compounds, respectively. Also, these 18-C-6-TA covalently bonded CSPs were compared to a commercially available Crownpak CR CSP prepared by coating chiral crown ether as a chiral selector on ODS column. (omitted)

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.220.3-220.3
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• 2003

Enantiomers of pindolol were prepared by chromatographic method. Racemic pindolol was derivatized with S-(-)-menthyl chloroformate((-)-MCF) forming its diastereomer, R-(+)-pindolol-(-)-MCF and S-(-)-pindolol-(-)-MCF. The diastereomer mixture was then chromatographically resolved to each diastereomer. Each diastereomer was further hydrolyzed with alkali to each enantiomer quantitatively. Racemization was not occurred in this process. Pindolol enantiomers were recovered producing good yield over 30% over all process.

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.224.2-224.2
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• 2003

Pyrethroic acids are essential chiral intermediates of the pyrethroids, which account for about 25% of the world insecticide market and are found to be some of the most effective commercially available pesticides. It was demonstrated that polysaccharide-derived chiral stationary phases (CSPs) are very efficient for the separation of the enantiomers of pyrethroid acids. It was observed that the enantioseparation of pyrethroic methyl ester and ethyl derivatives was well accomplished on brush-type WhelkO-1. (omitted)

• Bulletin of the Korean Chemical Society
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• v.31 no.3
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• pp.620-623
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• 2010

A brush type chiral stationary phase (CSP 2) derived from ${\alpha}$-amino ${\beta}$-lactam was prepared for the separation of the enantiomers of ${\beta}$-blockers. Compared to the CSP derived from ${\alpha}$-amino phosphonate (CSP 1), in general, the conformationally rigid CSP 2 showed greater scope and much enhanced enantioselectivity for the resolution of ${\beta}$-blockers. The effect of various salt additives on enantioseparation of ${\beta}$-blockers in the mobile phase was investigated. The unusual effect of temperature on the chromatographic behaviors was observed on CSP 2. It also afforded appreciable increases in enantioselectivity without significantly affecting resolution, as the column temperature was reduced.